1. Field of the Invention
The present invention relates to a method for fabricating a liquid crystal display (LCD) device, and more particularly, to a method for forming a pattern and a method for fabricating an LCD device using the same.
2. Discussion of the Related Art
Ultra thin flat panel LCD devices, of a thickness of several centimeters, have been used in notebook computers, monitors, spacecraft and airplanes, for example, because of their low power consumption and portability.
The LCD device may include lower and upper substrates facing each other with a predetermined interval therebetween, and a liquid crystal layer formed between the lower and upper substrates and sealed by a sealant.
The lower substrate may include gate and data lines formed perpendicularly to define a pixel region, a thin film transistor as a switching element formed adjacent to a crossing of the gate and data lines, and a pixel electrode connected to the thin film transistor and formed in the pixel region. The upper substrate may include a light-shielding layer to prevent light leakage in areas except the pixel region, a color filter layer of red (R), green (G), and blue (B) to represent colors in the area corresponding to the pixel region, and a common electrode formed on the color filter layer.
The LCD device includes the above various elements which are fabricated by repeated steps. The various elements may vary in shape by photolithography.
Hereinafter, a method for forming a pattern by related art photolithography will be explained with reference to the accompanying drawings.
FIGS. 1A to 1E are cross sectional views illustrating a method for forming a pattern by related art photolithography.
As shown in FIG. 1A, a pattern material layer 20 and a photoresist layer 30 are sequentially formed on a substrate 10.
As shown in FIG. 1B, after a mask 35 having a predetermined pattern is positioned above the photoresist layer 30, light is applied onto the photoresist layer 30 through the mask 35.
Referring to FIG. 1C, the photoresist layer 30 is selectively removed by development, whereby the photoresist layer 30 is patterned. In this case, the photoresist layer 30 may be formed of a positive type or a negative type photoresist. For the positive type photoresist, the portion irradiated with light is removed. For the negative type photoresist, the portion not irradiated with light is removed.
As shown in FIG. 1D, the pattern material layer 20 is selectively etched by using the patterned photoresist layer 30a as a mask. In this case, the process of removing the patterned photoresist layer 30 uses a photoresist stripper.
FIGS. 2A and 2B illustrate the process of removing the photoresist layer 30a by using a related art photoresist stripper.
As shown in FIG. 2A, a spacer 50 is positioned on the bottom of a container, and the container is filled with the photoresist stripper 40. Then, the substrate having the photoresist layer 30a is dipped into the container filled with the photoresist stripper 40, whereby the photoresist layer 30a is removed from the substrate as illustrated in FIG. 1E.
As shown in FIG. 2B, the photoresist stripper 40 is sprayed onto the substrate through a nozzle 45, thereby removing the photoresist layer 30a from the substrate. However, the photoresist stripper is expensive, and results in an additional cost for the disposal of photoresist stripper. The cost for the disposal of photoresist stripper corresponds to about 20% of the entire fabrication cost. Furthermore, environmental contamination may result from the disposal of photoresist stripper.